startVideoRecording method 
    
      
Future<void>
startVideoRecording(
)
      
     
    
    
  Implementation
  Future<void> startVideoRecording() async {
  if (!initialized) {
    _uiHandler.showSnackBar('Couldn\'t find the camera!');
    return;
  }
  if (value.isRecordingVideo) {
    _uiHandler.showSnackBar('Recording is already started!');
    return;
  }
  try {
    await controller.startVideoRecording();
    value = value.copyWith(
      isRecordingVideo: true,
      isRecordingPaused: false,
    );
  } on CameraException catch (e) {
    _uiHandler.showExceptionSnackbar(e);
    value = value.copyWith(isRecordingVideo: false);
    return;
  }
}